The invention relates to an image recording apparatus for recording an image on paper being transported on a paper transport path; and more particularly to an image recording apparatus provided with a unit pulling-out mechanism for pulling a unit out of the apparatus.
In electrophotographic image recording apparatus, paper is fed from a paper feeding section to an image recording section where an image is formed on the paper. Then the paper is output to a paper output section. Paper jams sometimes occur on a paper transport path leading from the paper feeding section, through the image recording section, to the paper output section. Paper jams are likely to occur particularly in the image recording section. This is because paper tends to be curled while undergoing various processes in the image recording section such as: a developer-image transfer process performed by a transfer device; or a fusing process performed by a fusing device.
Some image recording apparatus are provided with a paper transport path that includes a reversing transport path for use in duplex image formation (an image is formed on both sides of paper). In duplex image formation, paper with an image formed on a first side is reversed in the reversing transport path and transported back to the image recording section. Such a paper transport path has several bifurcations and confluences. Paper jams are likely to occur at the bifurcations and confluences since the transport direction of paper is changed there.
In the event of a paper jam occurring in part of the paper transport path, image recording apparatus stop paper transport throughout the paper transport path, and then suspend an image forming process until all paper sheets present on the paper transport path are removed. JP H09-134050A discloses an image recording apparatus provided with a removable image recording section. The image recording section has openable side walls and can be pulled out to the front side of the apparatus. This arrangement facilitates removal of paper jammed in the image recording section.
In the apparatus, however, only part of the paper transport path located in the image recording section can be exposed by pulling out the section and opening the side walls, and it is therefore difficult to remove jammed paper from unexposed parts of the paper transport path. Also, it is necessary for a user to open all of the side walls to check to see if all paper sheets are removed from the paper transport path.
As a solution to the above-described problems, an image recording apparatus has been proposed that includes: a first pullout unit that can be pulled out to the front of the apparatus; and a second pullout unit that can be pulled out to the lateral side of the apparatus with the first unit pulled out of the apparatus. The first unit has a first transport path, as part of a paper transport path, positioned therein. The second unit has a second transport path, as another part of the paper transport path, positioned therein.
The second transport path is separated from the first transport path by pulling the second unit out of the first unit, so that a large part of each of the first and second paths can be exposed.
When no restriction is imposed on the movement of the first and second units, however, it is impossible to prevent the second unit from being pulled out of the first unit with the first unit not fully pulled out of the apparatus, or the first unit from being inserted into the apparatus with the second unit not fully retracted in the first unit. Thus, the second unit may come into collision with the apparatus and cause malfunctions of, or damage to, the apparatus.
In view of the foregoing, a feature of the invention is to provide an image recording apparatus including a unit pulling-out mechanism that prevents malfunctions of, and damage to, the apparatus by restricting movement of the first and second pullout units in a situation when there is a possibility of the second unit coming into collision with the apparatus.